Flicker is a problem in which the radiant intensity of lights changes significantly due to voltage fluctuations generated when large power loads are turned on or off in an electrical system. Such flicker can occur when the healing element or elements of an imaging device, such as a printer, are powered. In such a case, incandescent or fluorescent lights in the room in which the imaging device is used may noticeably flicker.
Attempting to address the flicker problem by increasing the frequency at which the heating element or heating elements are switched, thereby placing the flicker frequency beyond that which the human eye can detect, may introduce additional design challenges. For example construction of the input power filter to avoid resonance with the switching electronics may be relatively costly. Further increasing the switching frequency to reduce the construction cost of the input filter may increase the power dissipated in the components used to control the switching of the power applied to the heating elements.